package com.yangyu.springcloud.lb;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author 一碗鱼汤面
 * @version V1.0
 * @Package com.yangyu.springcloud.lb
 * @date 2021/2/21 20:52
 */
@Component
public class MyLoadBalancer implements MyLb {

    private AtomicInteger atomicInteger = new AtomicInteger(0);

    public final int getAndIncrement() {
        int current;
        int next;
        do {
            current = this.atomicInteger.get();
            next = current >= Integer.MAX_VALUE ? 0 : current + 1;
        }while (!this.atomicInteger.compareAndSet(current, next));
        System.out.println("next============= " + next);
        return next;
    }

    @Override
    public ServiceInstance instance(List<ServiceInstance> serviceInstances) {
        int index = getAndIncrement() % serviceInstances.size();

        return serviceInstances.get(index);
    }
}
